question about pc fan wiring to plug in to wall.

Discussion in 'Grow Room Design/Setup' started by bowlpirate, May 25, 2010.

  1. So ive got two small pc fans that i want to run for exhaust, they say on them; dc 12v 0.24a -sb on the one, and dc 12v 0.18a -f00 on the smaller one.

    I have a bunch of random adapters in the garage i can cut up, so i want to know if any of them will work before i go out and buy a new one to cut up.

    the smallest adapter says; ac adaptor
    input 120v-60hz 4w
    output 4.5v dc 300ma
    class 2 transformer

    mid sized one says ac adaptor
    input 120vac 60hz 16 w
    output 12vdc 800mA
    class 2 transformer

    biggest says ac...

    input 120vac 60hz 29w
    output 12vdc 1.6 a

    Im not sure if any of these will work, and i really dont want to start a fire or anything so im willing to buy the proper adapter, i just dont know what one that is.
  2. #2 Dirtbud, May 25, 2010
    Last edited: May 25, 2010

    If you had the proper background in electric circuits I'm sure it could work, HOWEVER you can go buy them already for what your need for ~ $9. It will have the 4pin plug, and you can hard wire positive and negative on that. That is what I did. I'm sure you can easily find what I'm talking about searching around.
  3. The 12v 800mA will work fine for those two fans. It's always a good idea to hook them up and let run for a few hours while keeping and eye on them to make sure they don't get too hot.

  4. that's what i was thinking, the two fans should run .42 amps and that adapter should be good for .800 amps i believe.

    i would hook it up in a parallel circuit like this; correct?

    black being ground, red being power from the adapter, and dark red being power wire from fans and blue(black but for the drawing they are blue) for ground from the fans.


    Uploaded with
  5. Do you not have any extra Power Supplys!? You can use a jumper wire from the mainboard power to make the Power Supply stay running then you can use the same fan connections that are connected.....
  6. #6 Dirtbud, May 25, 2010
    Last edited: May 25, 2010
    Yes that is a parallel setup. If you were worried about amps, you could always use some fuses. I would think that the more amps, the faster the fan speed until it reached maximum speed. Make sure your wires don't overheat.
  7. Wallwarts are incredibly shitty power supplies. "12v at 800ma" means "if the current is 800ma, it will put out 12v". If the current is not 800ma, the output will not be 12v. Discovered this the hard way.

    However, with fans, it really doesn't matter that much. That will work, but i'd just use a computer power supply with a jumper on power switch... I'm planning to run those computer power connectors all around my appartment, personally...
  8. Just saying that's the easiest way... because you have multiple 12V rails you can use.... which each provide suffecient enuf power to run 10 fans easy per 12v rail.....

    If you can run a quad core, 2 video cards, 2 disk drives, 4 harddrives and 4 fans on a 550w power supply, I'm sure a 250w PS can run all the fans you need.

    btw..... Big fans spin slower, which are quieter and cost effecient (90mm+)

    They produce decent CFM for their price and power usage...

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